In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: Fix data-race on iso_pi fields in hci_get_route calls… (CVE-2026-63871)
A data-race vulnerability in the Linux kernel Bluetooth ISO subsystem was fixed. The issue involved concurrent access to iso_pi fields in hci_get_route calls without proper locking, leading to potential data races detected by KCSAN. The flaw affected functions iso_connect_bis(), iso_connect_cis(), iso_listen_bis(), and iso_conn_big_sync(). The fix involves snapshotting the relevant fields under lock_sock() before use to prevent concurrent modification.
AI Analysis
Technical Summary
The Linux kernel Bluetooth ISO subsystem had a data-race vulnerability (CVE-2026-63871) caused by accessing iso_pi(sk)->dst, iso_pi(sk)->src, and iso_pi(sk)->src_type fields without holding the lock_sock() lock in several functions calling hci_get_route(). These fields could be concurrently modified by connect() or setsockopt() on the same socket, resulting in data races detected by the Kernel Concurrency Sanitizer (KCSAN). The vulnerability was resolved by snapshotting these fields under lock_sock() before calling hci_get_route(), eliminating the race condition.
Potential Impact
The vulnerability could lead to data races in kernel memory, potentially causing undefined behavior or kernel instability. No direct exploit in the wild is known, and no further impact details such as privilege escalation or denial of service are provided.
Mitigation Recommendations
A fix is available and has been applied in the Linux kernel to snapshot iso_pi fields under lock_sock() before use. Users should update to the fixed kernel version once available. Patch status is not explicitly confirmed in the provided data; check the official Linux kernel advisories or vendor updates for the exact fixed versions and apply updates accordingly.
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: Fix data-race on iso_pi fields in hci_get_route calls… (CVE-2026-63871)
Description
A data-race vulnerability in the Linux kernel Bluetooth ISO subsystem was fixed. The issue involved concurrent access to iso_pi fields in hci_get_route calls without proper locking, leading to potential data races detected by KCSAN. The flaw affected functions iso_connect_bis(), iso_connect_cis(), iso_listen_bis(), and iso_conn_big_sync(). The fix involves snapshotting the relevant fields under lock_sock() before use to prevent concurrent modification.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel Bluetooth ISO subsystem had a data-race vulnerability (CVE-2026-63871) caused by accessing iso_pi(sk)->dst, iso_pi(sk)->src, and iso_pi(sk)->src_type fields without holding the lock_sock() lock in several functions calling hci_get_route(). These fields could be concurrently modified by connect() or setsockopt() on the same socket, resulting in data races detected by the Kernel Concurrency Sanitizer (KCSAN). The vulnerability was resolved by snapshotting these fields under lock_sock() before calling hci_get_route(), eliminating the race condition.
Potential Impact
The vulnerability could lead to data races in kernel memory, potentially causing undefined behavior or kernel instability. No direct exploit in the wild is known, and no further impact details such as privilege escalation or denial of service are provided.
Mitigation Recommendations
A fix is available and has been applied in the Linux kernel to snapshot iso_pi fields under lock_sock() before use. Users should update to the fixed kernel version once available. Patch status is not explicitly confirmed in the provided data; check the official Linux kernel advisories or vendor updates for the exact fixed versions and apply updates accordingly.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-5243-p4qj-j66v
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63871"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5d27ac2a4a8d5989130622
Added to database: 07/19/2026, 19:38:20 UTC
Last enriched: 07/19/2026, 20:14:19 UTC
Last updated: 07/20/2026, 11:39:58 UTC
Views: 11
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